utah dude:dude it would be cool if we could have chloroplasts in our skin. instead of eating you could lay-out.

I'm slightly surprised that more vertebrates don't have symbiotic algae in their skin. Then again most vertebrates are not naked but instead have hair or feathers that block sunlight. The ancestors of modern humans only lost their hair maybe 2 million years ago which is a short time to generate some magic combination of mutations that would support algae Likewise other African animals such as elephants and rhinos probably haven't been hairless long enough to pick up such an endosymbiosis.

I'm sure there will be more lizards and amphibians found with algal symbionts but wonder why there are none that are bright green heavy algal users, much less none found yet that have incorporated chloroplasts into their skin cells.

HairBolus:utah dude: dude it would be cool if we could have chloroplasts in our skin. instead of eating you could lay-out.

I'm slightly surprised that more vertebrates don't have symbiotic algae in their skin. Then again most vertebrates are not naked but instead have hair or feathers that block sunlight. The ancestors of modern humans only lost their hair maybe 2 million years ago which is a short time to generate some magic combination of mutations that would support algae Likewise other African animals such as elephants and rhinos probably haven't been hairless long enough to pick up such an endosymbiosis.

I'm sure there will be more lizards and amphibians found with algal symbionts but wonder why there are none that are bright green heavy algal users, much less none found yet that have incorporated chloroplasts into their skin cells.

It's simply that you get much, much more energy from eating other things that spend all their time concentrating the suns energy. Even better, you can eat things that spend all their time eating things that spend all their time concentrating the suns energy. You have to be big with a large surface area to take in a lot of energy from the sun, and you don't get much left over for other things, which is why grass grows out to cover the ground as much as possible and why trees put out all these branches and leaves, and why plants tend to be largely stationary or passive. The total surface area of your body is crap compared to a small shrub because you have to worry about staying warm enough to function.

LrdPhoenix:You have to be big with a large surface area to take in a lot of energy from the sun, and you don't get much left over for other things, which is why grass grows out to cover the ground as much as possible and why trees put out all these branches and leaves, and why plants tend to be largely stationary or passive.

To enlarge on this: photosynthesis is approximately 5% efficient at turning incident sunlight into energy. Solar flux at noon is around 1 MWatt per square meter. Average skin surface area for men is 2 sq meters, which means maybe 0.9 sq meters is usable at any given time. So, at full noon, a stationary human male oriented optimally can gather 45 watts of energy. Basal metabolic rate is close to 80 watts, which means that with optimal conditions a solar-powered human would basically run a 35 watt energy deficit.

theorellior:LrdPhoenix: You have to be big with a large surface area to take in a lot of energy from the sun, and you don't get much left over for other things, which is why grass grows out to cover the ground as much as possible and why trees put out all these branches and leaves, and why plants tend to be largely stationary or passive.

To enlarge on this: photosynthesis is approximately 5% efficient at turning incident sunlight into energy. Solar flux at noon is around 1 MWatt per square meter. Average skin surface area for men is 2 sq meters, which means maybe 0.9 sq meters is usable at any given time. So, at full noon, a stationary human male oriented optimally can gather 45 watts of energy. Basal metabolic rate is close to 80 watts, which means that with optimal conditions a solar-powered human would basically run a 35 watt energy deficit.

I would think that a small lizard that often spends time basking in the sun would gain from having skin chloroplasts, though I don't know how to work the figures, Even if it only contributed 8% of daily metabolism needs it would be an advantage.

theorellior:LrdPhoenix: You have to be big with a large surface area to take in a lot of energy from the sun, and you don't get much left over for other things, which is why grass grows out to cover the ground as much as possible and why trees put out all these branches and leaves, and why plants tend to be largely stationary or passive.

To enlarge on this: photosynthesis is approximately 5% efficient at turning incident sunlight into energy. Solar flux at noon is around 1 MWatt per square meter. Average skin surface area for men is 2 sq meters, which means maybe 0.9 sq meters is usable at any given time. So, at full noon, a stationary human male oriented optimally can gather 45 watts of energy. Basal metabolic rate is close to 80 watts, which means that with optimal conditions a solar-powered human would basically run a 35 watt energy deficit.

The answer to this is genetic engineering. The way we "humans" will conquer the stars is through some genetically engineered animal/plant hybrid. The truth is that when it comes to Star Trek future generations will look more like the aliens than we will look like us.

I used to catch yellow spotted salamanders when I was a child. So close and yet so far from a scientific discovery that would shake the very definition of plant and animal.

There's a sea slug which has algae in it and which has incorporated genes from the algae.

Multicellular organisms, according to Lynn Margolis, have incorporated bacteria twice, once as chloroplasts (plants) and once as mitochondra (animals). Both mitochondria and chloroplasts have been symbiotic with their hosts for so long they the host has a number of key genes acquired from the endosymbotic bacteria.

Apparently photosynthesis is so valuable that it's worth stealing more than once.

We are well on our way to evolving planimals. Maybe we can create Manimals in a few decades with genetic engineering. And possibly instead of stupid furries we will have stupid werewolves, mermaids, centaurs, etc.